Machine for grinding drill bits



. 13, 1938. F, DlXON v 2,139,938

MACHINE FOR GRINDING DRILL BITS Filed Dec. 4, 1937 5 Sheetsheet 1 311/1)Wwto't/ v r 76 Fax fie Dixon Dec. 13, 19%. F N 2,139,938 I MACHINE FORGRINDING DRILL BITS Fil ed Dec. 4, 1937 s Sheetsheet 2 T gmwm 7.11.1?

" v Fife Dixon Dec. 13, 1938. F. DIXON MACHINE FOR GRINDING DRIL L BITS5 Sheets-Sheet 5 Filed Dec. 4, 1957 Fate Dixon Patented Dec. 13, 1938their MACHINE FOR GRINDING DRILL BITS Fate Dixon, Durham, N. 0.,assignor of one-half to Samuel A. Poole, Durham, N. 0.

Application December 4, 1937, Serial No. 178,167

Claims.

My invention relates to a machine for sharpening or grinding the ends ofdrill bits or the like.

An important object of the invention is to provide a machine of theabove mentioned character,

5 having proper adjustments for grinding the angularly disposed facesupon the drill bit.

A further object of the invention is to provide a machine of the abovementioned character, the grinding action of which is manuallycontrolled.

A further object of the invention is to provide a machine of the abovementioned character so constructed that the drill bit is manually rockedupon the grinding surface from the leading point to the trailing point.

A further object of the invention is to provide means for bodily raisingand lowering the drill bit during the grinding action to properlydistribute the wear upon the rotary grinding element or stone.

A further object of the invention is toprovide a stop to engage with thedrill bit when properly set in the chuck or holding jaws for grindingone face, and adapted to engage with the bit to properly locate the samein the chuck so that the 25 other face will be ground at the same angle.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings forming a part 30 of this application andin which like numerals are employed to designate like parts throughoutthe same,

Figure 1 is a perspective view of a machine embodying my invention,

Figure 2 is a plan View of the same,

Figure 2a is an enlarged detailed view of the carriage movementindicating means,

Figure 3 is a side elevation of the same, showing the clamp holding thebit generally parallel 40 to the grinder and spaced therefrom,

Figure 3a is a detailed section taken on line 3a3a of Figure 3,

Figure 3b is a detailed section taken on line 3b-3b of Figure 3,

Figure 4 is a side elevation of the machine, parts in section, with thebit clamp swung to a position to hold the bit in an angular position forcontact with the rotary grinder,

Figure 4a is a. detailed section taken on line 50 4a--4a of Figure 3,

Figure 5 is a plan view of the machine, showing the parts in theadjusted position as shown in Figure 3,

Figure 6 is a side elevation, parts in section,

with the bit clamp moved upwardly and inwardly with respect to thegrinder,

Figure 7 is a side elevation of the bit clamp showing the gage rod,

Figure 7a is an enlarged end elevation of the bit, associated elementsbeing shown in elevation and broken away,

Figure 8 is a transverse section taken on line 88 of Figure 7,

Figure 9 is a plan View of the grinder, with the bit contactingtherewith and shown in section, and,

Figure 10 is a similar view, at right angles to ings I'l, rotatablyreceiving a horizontal shaft l8, driven by a pulley l9, engaged by abelt 25, in turn driven by the rotary element of any suitable primemover.

horizontal shaft Rigidly mounted upon the IB is a rotary grindingelement or stone 2|, clamped to the shaft l8 for rotation therewith, byany suitable means, and preferably in a manner whereby the grindingelement may be longitudinally adjusted upon the shaft it.

A vertically swinging frame 22 is mounted upon the vertical arms I6,comprising side bars 23, the forward ends of which have openings 24 topivotally receive a horizontal shaft 25, secured to the arms IS. Thearms 23 are rigidly connected by horizontal rods 26, and these rods 26are parallel with the rotary shaft 18.

Slidably mounted upon the guide shafts 26 of the frame 22 is 28, toreceive the a carriage 21, having openings rods 26. This carriage isadapted to have rectilinear reciprocatory movement and is providedbetween the openings 28 with a screw-threaded opening 29, for receivingthe screw-threaded portion 30 of a rotary operating shaft 3 I.

One reduced end 32 of the shaft 3! is rotatable within the opening 33;while the opposite end portion of the shaft is rotatable within anopening 34, and the shaft 3| has collars 35,

clamped thereon,

jacent side 23.

upon opposite faces of the ad- It is thus seen that the screw threadedshaft 3i can turn with respect to the sides 23 but cannot movelongitudinally with relation thereto.

The shaft 3! is turned by a knurled head 35 or the like. It is thus seenthat by turning the shaft 3|, the carriage may be moved in a directionlongitudinally of the shaft IS. The extent of movement of the carriagemay be indicated by a scale 36 formed upon the sleeve 35, with a pointer3'! formed upon the adjacent arm 23. The scale 36 is preferablycalibrated in one-thirty-second of an inch, starting from zero andextending in opposite directions. The scale 33 will indicate when thecarriage 21 has been shifted longitudinally with respect to the grindingelement 2| for one-thirty-second of an inch or any multiple thereof. Anyother suitable form of calibration may be used, if desired.

The carriage 21 is provided near its rear end with a verticalcylindrical opening 38, to rotatably receive a sleeve 39, projectingabove the carriage and having a disc 49' preferably formed integraltherewith, This disc is providedwith a pointer 4! to coact with a scale42, formed upon the rear end of the carriage 21, as shown. This scale isgraduated in degrees for denoting the angular disposition of the edge ofthe cutting end of the bit, with respect to the end face of the rotarygrinder. The end face of the bit is ordinarily beveled at about 45 withrespect to its longitudinal axis and when this bevel is desired, pointer4! registers with the degree designated 45 in the scale 42. To decreasethe angle of bevel on the bit, the disc 40 would be turnedcounterclockwise, while to increase the same the disc 46 would be turnedclockwise. Means are provided to lock the sleeve 39 to the carriage 2'!-in the selected adjusted position, comprising a set screw 43, having aknurled head 44 or the like. Rotatably mounted within the adjustablesleeve 33 is a vertical post 45, carrying a stop element 43, operatingwithin a segmental slot 41, formed in the sleeve 39, to engage an endwall 48, to limit the turning movement of the vertical post 45 in acounterclockwise direction, Figure l, to bri'ngth'e bevel face of thebit into contact with the end face of the rotary grinder. When the stopelement 45 engages the end wall 48, the selected angle for the edge 49of the face of the bit is determined. This angle is ordinarily 45 withrespect to the longitudinal axis of the bit although it may be increasedor decreased.

Rigidly secured to the upper end of the post 45 is a head 50, having ahorizontal opening M, to pivotally receive a generally horizontal shaft52, having a handle 53 rigid-1y secured thereto. Mounted upon the shaft52 is a collar 54, adapted to be clamped to the shaft by a set screw'5 5or the like. This collar carries a stop finger 56, operating above thehead 59 and to contact with the top of the head when the shaft 52 isturned clockwise, Figure 5, to the limit of its clockwise movement. Whenthe stop finger 56 engages the head 53, the bit preferably has itslongitudinal axis disposed at about 45 from the vertical. This preventsany possibility of the rotary grinder swinging the bit downwardly duringthe grinding! action. The angular position occupied by the bit withrespect to its longitudinal axis may be varied by turning the collar 54upon the shaft 52 and again clamping the same to the shaft.

The work or bit holding device or chuck comprises a stationary jaw 51,rigidly secured to the shaft 52 and this stationary jaw coacts with anopposed movable jaw 58, rigidly secured to a pair of rods 59, slidablewithin openings 63'- formed in the jaw 51. The rods 59 are rigidlysecured to a cross head 6!, having a screw-threaded opening 32, forreceiving a screw-threaded rod 63, turned by a milled head 64. The innerend of this screwthreaded rod is arranged to contact with the stationaryhead 60 and thereby draw the movable jaw 58 toward the stationary jaw.The stationary jaw is provided with a V-shaped notch to receive the sideof the bit 96, to cause the same to be centered, as shown. It is thusseen that the jaws 51 and 58 will clamp the bit 63 between them andproperly hold the bit during the grinding action. Rigidly attached tothe stationary jaw 51 is a guide rod 6?, which is preferably square incross-section and slidably receives thereon a carriage 68, which isclamped in adjustment at a selected longitudinal position upon the rod61 by a set screw 69 or the like. The carriage 38 has outwardlydiverging jaws l8, affording a V-shaped recess H, receiving the rear endof the bit 66. The guide rod 6? has a handle 12, as shown.

The stationary jaw 51 is provided upon its forward face with a housing13, rigidly secured thereto, having a V-shaped groove 74, to receive agage rod 75. The gage rod is clamped in position by a set screw 16,turned by a handle Ti. The gage rod is set to engage with the face( 78of the bit when the major portion of its edge i9 is vertical, whenlooking down upon the bit when in a generally horizontal position. Afterone face or bevel at the end of the bit has been ground, the bit isturned around in the work clamp, by proper manipulation of the partsthereof and the gage rod 75 will then engage the face 39', so that theedge 8! of the bit will be vertically arranged, This renders it possibleto quickly adjust the bit within the holder or clamp and render itcertain that the two bevel faces will be ground at precisely the sameangle.

The operation of the machine is as follows:

The sleeve 39 may be adjusted to define the angle of bevel 49, Figure 9,and if this is to be 45 with respect to the longitudinal axis of thebit, the pointer 4| registers with 45 in the scale 42, and the sleeve 39is clamped to the carriage in this selected adjusted position. Themovable jaw 58 is now moved from the stationary jaw 5'! so that the bit66 may be inserted between the jaws, and the rear end of the bit willengage within the V-shaped notch H. The rod 52 and the rod 5'! are nowraised, the stop finger 56 engaging the top of the head 5!, and thevertical post 45 is turned until stop pin 43 engages the end wall 48. Inthis adjusted position, the bevel end 49 of the bit should substantiallycontact the end face of the rotary grinder, but if it does not, thecarriage 38 is moved forwardly from the rod 61, until this occurs, afterwhich the carriage 68 is clamped to the rod and the inner jaw 58 ismoved toward the stationary jaw 51 to securely clamp the bit 63 betweenthese jaws. Before the final clamping adjustment of the movable jaw 58,care is taken that the edge 79 of the bit is vertically disposed, whichwill position the bevel face 83 of the bit, next to the rotary grinder,in the proper position to contact with the end face of the grinder andbe ground thereby. The gage rod 15 is sent to contact with the face l8,and is clamped in this positionQso that it may readily engage the face88, so that the edge 8| of the bit will be vertical when the bit isreversed, for grinding the bevel face 82. With the parts thus adjusted,and the rotary grinder rotating toward the operator, the operatorengages the handles 53 and i2 thereby raising the frame 22 and theelements carried thereby. The bevel face 83 of the bit is therebybrought into contact with the end face of the grinder, and at theinstant of contact the handle 12 is swung downwardly, while the handle53 is moved upwardly and inwardly. Particular attention is called to thefact that the bit is held to one side of the shaft 53 and is thereforeeccentric with respect to the shaft and the downwardly swinging movementof the handle 72 causes the face 83 to be ground into a slightly convexsurface, Figure 10. The leading end of edge 69 is thus shifted from theend face of the grinder while the trailing end of this face is moved incontact with the grinding face. The inward movement of the bit withrespect to the rotary grinding element distributes the Wear upon thegrinding element. When it is desired to increase the extent of grindingaction, the bit is shifted bodily longitudinally toward the grindingwheel by advancing the carriage 21, by turning the operating shaft 3|.It is thus seen that the bit holder is capable of swinging in ahorizontal plane toward the rotary grinder and also in a vertical plane,and the work holder may be also bodily raised and lowered with respectto the rotary grinder by' raising and lowering the swinging framecarrying the vertical post and the work holder may also partake ofrectilinear reciprocatory movement by sliding the carriage supportingthe post longitudinally of its rods.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of my invention or thescope of the subjoined claims.

Having thus described my invention, what I claim is:

1. In a machine for grinding the beveled end of a bit or the like, asubstantially vertical rotary grinder, a relatively stationary support,a vertically swinging generally horizontal support arranged upon oneside of and spaced from the rotary grinder and pivotally connected withthe relatively stationary support to turn upon an axis extendinglongitudinally of the axis of rotation of the grinder, a carriagemounted upon the vertically swinging support, means to bodily move thecarriage in a straight line with relation to the vertically swingingsupport in a direction longitudinally of the axis of rotation of thegrinder, a generally vertical supporting device mounted upon thecarriage and providing a turning axis arranged at generally a rightangle to the plane of the carriage, a member mounted upon the generallyvertical supporting device and permanently free to turn about theturning axis of the same within limits, a clamp disposed opposite theend of the rotary grinder and having means for holding a bit so that thelongitudinal axis of the bit is arranged generally at a right angle tothe end of the rotary grinder to present the end of a bit to the end ofthe grinder, and means to pivotally mount the clamping device upon themember so that the clamp is permalently free to be swung in a generallyvertical plane while the edge of the bit engages the end of the grinder.

2. In a machine for grinding the beveled end of a bit or the like, asubstantially vertical rotary grinder, arelatively stationary generallyhorizontal support, a vertically swinging support arranged upon one sideof the grinder and pivotally connected with the relatively stationarysupport to turn upon an axis extending longitudinally of: the axis ofrotation of the grinder, a carriage mounted upon the vertically swingingsupport, means to bodily move the carriage in a straight, line withrelation to the vertically swinging support in a directionlongitudinally of the axis of rotation of the grinder, a sleevepivotally mounted upon the carriage and having its turning axis arrangedgenerally vertically at generally a right angle to the plane of thecarriage, means to clamp the sleeve in the selected adjusted positionagainst turning movement, a generally vertical post having limitedturning movement in the sleeve, a clamp projecting to a positiongenerally opposite the end of the rotary grinder and presenting the bitheld therein to such end, a head carried by the post and having anopening arranged at substantially a right angle to the longitudinal axisof the post, and a shaft pivotally mounted within such opening andcarrying the clamp so that the clamp may be swung in a generallyvertical direction and a handle secured to the shaft to turn the sameupon its longitudinal. axis.

3. In a machine for' grinding the beveled end of a bit or the like, asubstantially vertical rotary grinder, a generally horizontal framearranged beneath the grinder in spaced relation thereto, means topivotally support the frame so that it may be swung vertically towardand from the periphery of the grinder, a carriage slidably mounted uponthe generally horizontal frame to move in a straight line which issubstantially parallel with the axis of rotation of the grinder, anoperating shaft secured to the frame and having screw threadedengagement with the carriage to move the same in the said straight line,a generally vertical sleeve mounted to turn upon the carriage, thesleeve and carriage having means to indicate the extent of turningmovement, means to clamp the sleeve to the carriage against turningmovement, a generally vertical post permanently freely pivotally mountedwithin the sleeve for turning movements within limits, a block rigidlysecured to the generally vertical post and having a generally horizontalopening, a generally horizontal shaft permanently freely pivotallymounted within the opening and having its forward end extending oppositethe end of the grinder, a stop having a turning adjustment upon theshaft and a part to engage the block to limit the turning movement ofthe shaft, a handle secured to the shaft to turn the same upon itslongitudinal axis, a clamp mounted upon that end of the shaft oppositethe end of the grinder and having means to hold the bit so that thelongitudinal axis of the bit will be arranged generally at a right angleto the shaft and the end of the grinder, and a handle secured to theclamp and projecting laterally outwardly from the same and disposed atgenerally a right angle to the first named handle.

4. In a machine for grinding the beveled end of a bit or the like, asubstantially vertical rotary grinder, a relatively stationary support,a generally horizontal support arranged beneath and spaced from therotary grinder, means to pivotally mount the generally horizontalsupport upon the stationary support so that it may be swung verticallytoward and from the grinder, a guide device mounted upon the generallyhori zontal support and extending longitudinally thereof and projectingbeyond one end of the rotary grinder, a carriage mounted upon the guidedevice, an adjusting screw to move the .carr-iage longitudinally of theguide device, a generally vertical post mounted upon the carriage andhaving a turning axis, the post projecting upwardly beyond the carriage,a generally horizontal shaft arranged above the carriage and mountedupon the upper end of the post and turning about the axis of the postand adapted to turn upon its longitudinal axis,,a clamp disposedopposite the end of the rotary grinder and mounted upon the generallyhorizontal shaft and having means to receive and hold the bit so thatthe longitudinal axis of the bit Will be arranged generally at a rightangle to the surface of the end of the rotary grinder, and means forraising the generally horizontal support and for turning the generallyhorizontal shaft to present the end of the bit to the end of the grinderat varying distances from the periphery of the grinder.

5. In a machine for grinding the beveled end of a bit or the like, asubstantially vertical rotary grinder, a relatively stationary support,a generally horizontal support arranged beneath and spaced from therotary grinder, means to pivotally mount the generally horizontalsupport upon the stationary support so that the generally horizontalsupport may be swung vertically toward and from the grinder, a guidedevice mounted upon the generally horizontal support and extendinglongitudinally thereof and projecting beyond one end of the rotarygrinder, a carriage mounted upon the guide device, an adjusting .screWto move the carriage longitudinally of the guide device, a generallyvertical post mounted upon the carriage and having a turning axis andprojecting upwardly beyond the carriage, a head mounted upon the post toturn generally horizontally about the turning axis of the post, saidhead having a generally horizontal opening, a rock shaft extendingthrough the generally horizontal opening, an adjustable stop mountedupon the rock shaft and having a part to engage with the head to limitthe turning movement of the rock shaft, a handle mounted upon the outerend of the rock shaft, a clamp arranged opposite one end of the rotarygrinder and mounted upon the rock shaft and having means for receivingand holding the bit so that the longitudinal axis of the bit is arrangedgenerally at a right angle to the face of the end of 1

